Ok, that movie was just a lot of fun. The casting was perfect - Matthew McConnaughey (almost had it right on the first try!), Steve Zahn, and Bill Macy were a great comic trio... and they actually let Al Giordino (Steve Zahn's "comic sidekick" character) have some incredible competence. Dirk Pitt would tell Al to do something, and not only would Al make sure it was done, and done well — he would make sure it was done funny.
Edit: I should also add that the scenery and the music were really good in the movie, too.
Important note for future movie-going expeditions though... If I'm going to be driving people from both Brookline and Arlington to Woburn for a movie, I will be in the car for an hour each way. Not that this is unacceptable or bad. It just needs to be accounted for.